Continuous draft gear



June 1935- c. E. ALMA ET AL CONTINUOUS DRAFT GEAR 2 Sheets-Shet 1 Filed June 17, 1951 ATNVENTORAS 'c. E. ALMA ET AL CONTINUOU DRAFT GEAR June 9, 1936.

Filed June 17, 1951 2 Sheets-Sheet 2 III/Ill) VIII/Ill Patented June 9, 1936 UNITED STATES ATET OFFICE CONTINUOUS DRAFT GEAR Application June 17, 1931, Serial No. 545,008 In Germany January 5, 1931 15 Claims.

The invention relates to draft gear for trains of cars and particularly for railway trains.

In the application, Serial No. 370,404, filed June 12, 1929, there is disclosed railway draft gear which is continuous and rigid throughout a group of cars under the normal conditions of use, is capable of elastic expansion or contraction in case of abnormal strain and further is capable of resuming rigidity in case of violent shock such as would endanger the car frame. In normal use,

such a draft gear avoids train slack with its resulting accumulation and accentuation of shock. Under abnormal circumstances, it allows a controlled train slack for the purpose of starting heavy trains or for cushioning unusual forces. And in the case of very heavy stresses or violent shocks, it provides means for taking up such shocks and transmitting them through the train independently of the individual car frames, so

that the danger of crushing or disruption of cars is very substantially reduced.

An object of the present invention is an improvement of the draft gear disclosed in our previous application in which the means for rent5edering the draft gear elastic under abnormal circumstances is also utilized to transmit pulling or buffing stresses from the draft gear to the car frame.

In general, the draft mechanism for each car comprises a pair of draw bar sections slidably supported by the car frame and provided with yielding means, called frame springs, by means of which forces of pulling and bumng stresses are transmitted from the draw bar sections to the car, in combination with short connecting means joining together the inner ends of the draw bar sections and permitting limited relative movement of the draw bar sections. Yielding means called rod springs are provided to oppose relative movement of the draw bar sections and such yielding means are so arranged that they may assist in transmitting draft and buffing strains from the draft gear to the car. With the draft or buffing stresses applied from one end only of the car, such yielding means operate at least upon a certain amount of force as if arranged directly between a draw bar section and the car frame. But with draft or buffing stresses exerted from both ends of the car, they transfer stresses directly from one draw bar section to the other.

Other objects, novel features and advantages of the invention will be apparent from the following specification and accompanying drawings, wherein:

Fig. 1 illustrates in horizontal section one form Val of apparatus adapted to be embodied in each car of a train of cars; 7 I

Figs. 2 and 3 are similar views of modified forms;

Fig. 4 is a modification of Fig. 1, and Fig. 5 is a section on the line 55 of Fig. 3.

Referring now to Fig. 1, a, a, represent longitudinal sills of a car frame; b, c, d, e, f, and g are abutments fixed to the sills a, a; and h, i, are cross sills or girders supported by the sills a, 0.. All of the foregoing elements are fixed with respect to the car frame.

The draft mechanism for each car includes a gear comprising in general draw bar sections I, 2, (shown only in part) each of which is substantially one-half as long as the car frame and which may be composed of rigid parts, and a short connector 3, rigidly attached to the inner end of the draw bar section 2, and having a lost motion connection with the draw bar section I. It will be understood that to the outer end of the draw bar sections respectively are connected coupler shanks or couplers of any suitable construction (not shown) in any desirable manner.

Each draw bar section I, 2, is elastically connected to the car frame, as for example, by frame springs 4 and 5, which encircle the draw bar sections and are interposed between followers 6 and 'I and 8 and 9 respectively, the followers being loosely mounted on the draw bar sections and normally being held in engagement with the abutments b, c, f, and g, by the springs 4 and 5. Sleeves or nuts II], II, I2, and I3 are provided on the draw bar sections I and 2 and are adapted respectively to engage the followers 6, I, 8, and 9. The sleeve I0 is adapted to engage the cross sill h to limit outward movement of the draw bar section I and the sleeve I2 is adapted to engage the cross sill i to limit inward movement of the draw bar section 2. A sleeve I4 is provided on the draw bar section I to limit inward movement thereof and outward movement of the draw bar section 2 is limited by contact of the connector 3 with the cross sill 2.

Draw bar section I is provided with a head I5 arranged in the connector 3 by means of which relative movement of the draw bar section and connector is limited. Followers I6 and II are loosely mounted on the draw bar section I and a rod spring I8 is interposed between said followers. In position of rest, the follower I6 contacts with the sleeve I I and also with the abutment 11, while the follower II contacts with one end of the connector 3 and with the abutment e. Rods I9 extend through a flange or lugs of the connector 3 and through the followers I6 and I1, these rods being provided with nuts 20 by means of which movement of the connector 3 to the right causes corresponding movement of the follower I6. A sleeve 2| surrounds the draw bar section I and is interposed between the head I5 and the follower I'I, whereby outward movement of draw bar section I causes corresponding movement of the follower II.

In the event of an outward pull on the draw bar section I, the followers I and II will be moved to the left thus compressing the springs 4 and I8 thereby transmitting stress resiliently from the draft gear to the car frame through both springs 4 and I8. In the event of an outward pull on the draw bar section 2, the same effect is secured through compression of the springs 5 and I8. In the event of an inward push on the rod I, the followers 6 and I6 are moved to the right, thereby compressing the springs 4 and I8, thereby transmitting stresses from the draw bar section through both springs 4 and I8 to the car frame. An inward push on the rod 2 produces a like effect through the compression of the springs 5 and I8. In the event of an outward pull on both draw bar sections or an inward push on both draw bar sections, the followers I6 and I I will be moved away from the abutments d and e and toward each other to compress the spring I8 which tends to oppose relative movement of the draw bar sections and stresses will be transmitted from the draw bar sections to the car frame merely by the frame springs 4 and 5. The movement of the draw bar sections I and 2 relative one to another upon push is limited preferably by meeting of the inner ends of the draw bar sections.

The modification disclosed in Fig. 2 differs from that disclosed in Fig. 1 in that the draft gear is rigid at all times to buffing stresses, but is elastic under draft stresses. In the position of rest, the inner end of draw bar section I is in contact with the inner end of draw bar section 2 and also the head I5 may be in contact with the end part of the connector 3 rigidly attached to the inner end of draw bar section 2. For the rest the arrangement is the same as in Fig. 1. In this modification, an outward pull on either the draw bar section I or the draw bar section 2 or on both draw bar sections has the same effect as described in connection with Fig. 1. In the event of an inward push upon one draw bar section or on both draw bar sections, there will be. no relative movement of the draw bar sections and. buffing stresses will be transmitted rigidly between the two draw bar sections.

In the modification disclosed in Figs. 1 and 2, the maximum travel of the rod spring equals the maximum travel of the frame springs (i. e., the maximum travel of a draw bar section). Therefore, in these modifications, in general, the full resistance of the rod spring and of one of the frame springs is available to oppose strong strain exerted at one car end. In the modification Fig. 2, the full resistance of all three springs is available in case of pushing strain.

In the modification disclosed in Fig. 3, the maximum travel of a frame spring 4, 5 is larger than the maximum travel of the rod spring I8 and the distance provided between the abutments d and e and followers I6 and. Il respectively in the position of rest, equals the difference between maximum travel of a draw bar section and maximum travel of the rod spring. The frame spring 5 lying between the followers 8 and 9 is affected by connector 3 upon pull and by nut I3 upon push. The travel of draw bar section 2 is limited by abutting of nut I3 on cross sill 2' upon pull and by abutting of nut 22 on sill 2' upon push. For the rest, the arrangement is similar to the arrangement in Fig. 1. Upon heavy pushing strain only from the left, the springs 4, I8, and 5 will be compressed until follower I'I comes in contact with abutment e. Then further compression of the springs 4 and I8 takes place and spring 5 remains pressed on abutment 9, but without increasing its compression. When the force of strain causes the nut I4 to come in contact with cross sill h, whereby the travel of draw bar section I is limited, the springs 4 and I8 are fully compressed.

Upon strong pull only to the left, the operation in general is similar to the above described, but instead of follower I'I, follower IE comes in contact with the adjacent abutment d and spring 5 is pressed on abutment f. Upon pull to the left the travel of the draw bar section I is limited by contact of nut II] with cross sill h.

Upon push from the right only or pull to the right only, the operation of spring I8 in general is similar to the above described operation of this spring and the operation of spring 5 and 4 is similar as above described for 4 and 5. Also for the rest, the operation in general is analogous to the above described operations.

Upon strains applied on both couplers of a car, the spring I8 is compressed by the relative movement of the draw bar sections I, 2, but the springs 4, 5 transmit a small part of the forces through the car frame. The relative movement of the draw bar sections is limited upon pull by the head I5 and upon pushing strain by meeting of the inner ends of the draw bar sections I and 2.

It is preferred that the maximum travel of the rod spring upon push and pull is equal and it is also preferred that the maximum travel of the draw bar section in the direction out of the car equals this travel in the direction into the car, but variation may be made by which the maximum travel of the draw bar section in the A5 direction out of the car is shorter than its maximum travel in the direction into the car. With such arrangement, full compression of the rod spring and also of the frame springs of one draw bar section in case of strain on one coupler will be available only upon push.

The embodiment of the invention disclosed in Fig. 4 differs from that disclosed in Fig. 1 in that a friction device 23 of the type well-known in the art interposed between the ends of the draw bar sections I and 2. By means of this friction device, resistance against bufling strains is increased. The friction device 23 is preferably connected to the ends of the draw bar section in such manner that it is effective on pushing strains and may be of any suitable structure. Fig. 5 (cross section through abutment e) illustrates convenient arrangement of abutment c and the lugs 25 provided on the connector 3. The rods I9 extend through followers I6, I1 and through the lugs 25 of the connector and carry nuts 29 as shown in Figs. 1, 2 or 3. Abutment 0 lies in another longitudinal plane than the lugs.

The lugs 25 need not be made in one piece with the connector, but they may for instance be provided on a circular shaped band which is slipped over on the connector and is held on the latter by means of a fiange on the connector or other convenable change may be made. Also the position of abutment d relative to the nuts engaging the follower I6 may be similar to the position of abutment 6 relative to the lugs 25, shown in Fig. 4. The said nuts may be substituted byheads of the rods l9, if necessary or advisable.

In all the modifications, the various springs preferably are of appropriate initial tension and capacity and so constructed and arranged with the associated parts that the draft gear is rigid in a group of cars for stresses less than a predetermined value and above a higher predetermined value and is elastic for stresses intermediate said values. The arrangement also is such that the rod spring it, under certain conditions assists with its full capacity in transmitting stresses from the draft gear to the car frame, thus providing additional spring capacity between the draft gear and car frame.

In all modifications high spring capacity is desirable in heavy cars. In the modifications of Figs, 1 and 2 it may be preferable that all springs have like initial tension. Especially in the modification, Fig. 3, it is advantageous to provide a high initial tension of the rod spring (e. g. an initial tension of 9,000 pounds or more). The initial tension of the frame springs may be considerably less. I High initial tension of the rod spring in Fig.3 is permissible because in the beginning of a stress or upon such stresses by which contact of a follower of the rod spring with an abutment of the car frame does not take place, the car frame is engaged only by the frame springs.

' The above arrangement provides the high spring capacity desirable for receiving bufiing stresses exerted on a car end in switching. The full resistance of the rod spring is added to that of a frame spring upon the application of a push to one of the draw bar sections. The full resistance of the rod spring is made available by making the maximum longitudinal travel of the connecting means equal to or in excess of the maximum compression of the rod spring. In the former case, the rod spring followers in the position of rest directly engage their abutments and in the latter case they are slightly spaced from such abutments. The first arrangement is especially useful where it is desirable or necessary that the travel of the frame springs be relatively small, while the second arrangement is useful for freight cars in which a long travel of the frame springs is desired. Preferably, the maximum travel of a frame spring corresponds to the maximum travel of the connecting means which in turn corresponds with the maximum travel of a draw bar section. In both arrangements, the rod spring renders the draft gear elastic in case of opposite strains and also performs the additional functionof assisting in resiliently transmitting force to the car frame.

.A draft gear embodying the present invention is rigid in a group of cars under normal conditions of use, elastic when subjected to abnormal conditions of use and again becomes rigid in the event of a very heavy stress or violent shock. In addition, in the event of an impact at one end of the draft gear of a car, greater spring capacity between the draw bar section and car frame is provided. In such event, the full resistance of the yielding means for rendering the gear elastic is added to the resistance of yielding means through which pressure is transmitted from the draw bar section to the car frame. It is of course understood that various modifications may be made in the structure above described without in any way departing from the spirit of the invention as defined in the appended claims.

What is claimed is:

1. In a railway draft gear, the combination with a car frame of a pair of slidably mounted aligned draw bar sections extending substantially the full length of the car frame, means connecting the inner ends of said sections and permitting limited relative movement thereof into rigid relation, yielding means for opposing relative movement of said sections, a pair of followers for said yielding means, abutments on the car frame for engagement by said followers, said followers being spaced from the abutments in the position of rest by a distance which equals the difference between the amount of the maximum travel of a draw bar section and the amount of the maximum travel of said yielding means.

2. In combination with a car frame, a pair of slidable alined draw bar sections extending substantially the full length of the car frame, a connector joining the inner ends of said sections and permitting limited relative movement thereof into rigid relation, a pair of followers slidably mountedon one of said draw bar sections, shoulders on said draw bar section, a spring interposed between said followers and tending to hold the same in contact with said shoulders, one of said followers being normally in contact with one end of said connector, means for transmitting pull between said connector and the other follower andiabutments on said car frame for engagement by said followers.

3. In combination with a car frame, a pair of slidable alined draw bar sections extending substantially the full length of the car frame, a connector joining the inner ends of said sections and permitting limited relative movement of the draw bar sections in one direction only from a position of rest into rigid relation, a pair of followers slidably mounted on one of said draw bar sections, shoulders on said draw bar section, a spring interposed between said followers and tending to hold the same in contact with said shoulders, one of said followers being normally in contact with one end of said connector, means for transmitting pull between said connector and the other follower and abutments on said car frame for engagement by said followers.

4. In combination with a car frame, a pair of slidable alined draw bar sections extending sub-' stantially the full length of the car frame, a connector joining the inner ends of said sections and permitting limited relative movement thereof into rigid relation, a pair of followers slidably mounted on one of said draw bar sections, shoulders on said draw bar section, a spring interposed between said followers and tending to hold said followers in contact with said shoulders, one of said followers being normally in contact with one end of said connector, means for transmitting pull between said connector and the other follower and abutments on said car frame for engagement by said followers, said followers being spaced from the abutments in the position of rest by a distance which equals the difference between the amount of the maximum travel of a draw bar section and the amount of the maximum travel of said spring.

5. In combination with a car frame, a pair of slidable alined draw bar sections extending substantially the full length of the car frame, a connector joining the inner ends of said sections and permitting limited relative movement thereof into rigid relation, a pair of followers slidably mounted on one of said draw bar sections, shoulders on said draw bar section, a spring interposed. between said followers and'tending to hold the same in contact with said shoulders, and abutments on said car frame for engagement by said followers, one of said followers being normally in contact with one end of said connector, means for transmitting pull between said connector and the other follower, said abutments being in spaced relation to said followers in the position of rest of said draw bar sections.

6. In combination, a car frame, a pair of slidable alined draw bar sections extending substantially the full length of the car frame, a connector joining the inner ends of said sections and permitting limited relative movement thereof into rigid relation, a pair of followers slidably mounted on one of said draw bar sections, shoulders on said drawbar section, a spring interposed between said followers and tending to hold the same in engagement with said followers, one of said followers being normally in contact with one end of said connector, means for transmitting pull between the connector and the other follower, abutments on said car frame for engagement by said followers, and a friction gear interposed between the ends of said draw bar sections to oppose movement thereof toward each other.

7. In a draft rigging for railway cars, the combination with coupler members at opposite ends of the car; of cushioning means opposing relative movement of each coupler member and the car; shock absorbing means; means for compressing said shock absorbing means, including pressure-transmitting means between one of said couplers and one end of said shock absorbing means and pressure-transmitting means between the other coupler and the other end of said shock absorbing means; and stop means on the car at opposite ends of said shock absorbing means and spaced therefrom a distance less than the maximum movement of said pressure-transmitting means whereby said shock absorbing means is operated after predetermined compression of said cushioning means to oppose movement of said coupler members with respect to the car.

8. In a draft rigging for railway cars, the combination with coupler means at opposite ends of the car; of a pressure-transmitting column member connected to each coupler and extending inwardly of the car; means yieldingly opposing movement of each column member with respect to the car and normally holding said column member in predetermined position; a shock absorbing mechanism interposed between the inner ends of the column members and opposing relative movement thereof toward each other; and fixed stop means on the car at opposite ends of said shock absorbing mechanism against which said shock absorbing mechanism is compressible, said column members when in said predetermined normal position holding said shock absorbing mechanism spaced from said fixed stop means.

9. In a draft rigging for railway cars, the combination with coupler members at opposite ends of the car; of cushioning means opposing movement of each coupler member and the car; a shock absorbing means; pressure-transmitting means between the couplers and the opposite ends of said shock absorbing means; and fixed stop means on the car at opposite ends of said shock absorbing means against which the opposite ends of said shock absorbing means are respectively compressible, said stops being spaced apart a distance lengthwise of the car, which is greater than the overall length of the shock absorbing means when fully expanded but less than said overall length of the shock absorbing means plus the bufiing movement of either of said pressure-transmitting means, whereby said shock absorbing means is bodily movable between said stops to an extent less than the full buffing movement of either of the coupler members.

10. In railway draft gear, the combination with a car frame of a pair of slidably mounted alined draw bar sections extending substantially the full length of the car frame, means connecting the inner ends of said sections and permitting limited relative movement thereof into rigid relation, yielding means for opposing relative movement of said sections, a pair of followers for said yielding means, abutments on the car frame for engagement by said followers, said followers being spaced from the abutments in the position of rest by a distance which equals the difference between the amount of the maximum travel of a draw bar section and the amount of the maximum travel of said yielding means.

11. In a draft rigging for railway cars, the combination with pressure transmitting bars extending inwardly from opposite ends of the car, of cushioning means opposing relative movement of each bar and the car, shock absorbing means 0 between the inner ends of said bars, and stop means on the car at opposite ends of said shock absorbing means and spaced therefrom a distance less than the maximum movement of said pressure transmitting bars whereby said shock absorbing means is operated after predetermined compression of said cushioning means to oppose movement of said pressure transmitting bars with respect to the car.

12. In a draft rigging for railway cars, the combination with pressure transmitting column members extending inwardly from opposite ends of the car; of means yieldingly opposing movement of each column member with respect to the car and normally holding said column member in predetermined position; a shock absorbing mechanism interposed between the inner ends of the column members and opposing relative movement thereof toward each other; and fixed stop means on the car at opposite ends of said shock absorbing mechanism against which said shock absorbing mechanism is compressible, said column members when in said predetermined normal position holding said shock absorbing mechanism spaced from said fixed stopmeans.

13. In a draft rigging for railway cars, the combination with pressure transmitting bars extending inwardly from opposite ends of the car; of cushioning means opposing relative movement of each bar and the car; a shock absorbing means between the inner ends of said pressure transmitting bars; and fixed stop means on the car at opposite ends of said shock absorbing means against which the opposite ends of said shock absorbing means are respectively compressible. said stops being spaced apart a distance lengthwise of the car, which is greater than the overall length of the shock absorbing means when fully expanded but less than said overall length of the shock absorbing means plus the buffing movement of either of said pressure transmitting bars, whereby said shock absorbing means is bodily movable between said stops to an extent less than the full buffing movement of either of said pressure transmitting bars.

14. In a draft rigging for railway cars, the combination of pressure transmitting bars extending inwardly from opposite ends of the car, resilient means opposing movement of each bar relative to the car, yoke means connecting the inner ends of said bars, one of said bars being movable inward- 1y of said yoke and having lost motion connection therewith, shock absorbing means associated with said yoke and bars for opposing relative movement of said bars, and fixed stop means on the car at opposite ends of said shock absorbing means and spaced therefrom a distance less than the maximum movement of said pressure transmitting bars whereby said shock absorbing mechanism is operated after predetermined movement of the pressure transmitting bars relative to the car.

15. In combination with a car frame, a pair of slidable alined draw bar sections extending substantially the full length of the car frame, resilient means between each draw bar section and the car frame for opposing movement of the section relative to the car frame, a connector joining the inner ends of said sections for limited relative movement thereof into rigid relation, shock absorbing means associated with said connector and draw bar sections for opposing relative movement thereof, and abutments on said car frame for engagement by the ends of said shock absorbing means, said abutments being in spaced relation to said ends in the position of rest of said draw bar sections.

CARL EGON ALMA.

LYDIA ALMA, Administratria: of the Estate of Maximilian Alma,

Deceased. 

